Apparatus and method of use for a PVC composite mattress frame

ABSTRACT

A mattress frame that is lightweight, durable, and minimizes material use. The apparatus includes a pair of side rails connected to a pair of end rails via four end caps to form a generally rectangular shape. The side rails and the end rails can vary in length and each of the side rails and end rails has an identical cross-section shape made up of five sections surrounding a slot. The end caps each include two tabs for insertion into the slots of the side rails and end rails. The side rails and end rails further include a pair of strengthening steel ribs. An alternate embodiment includes slats which extend from side rail to side rail or from end rail to end rail. Each slat has a generally U-shaped cross section and further includes two galvanized steel ribs running their entire length. Another alternate embodiment includes feet.

FIELD OF THE INVENTION

The present invention relates generally to mattress frames. In particular, the invention relates to a lightweight and high strength extruded polyvinyl chloride (PVC) composite mattress frame.

BACKGROUND OF THE INVENTION

A mattress frame, commonly known as a set of box-springs, is a type of bed base typically consisting of a sturdy wooden frame covered in fabric, and containing springs. In use, the mattress frame is placed on a metal bed frame which supports the mattress frame and acts as a stand to raise the bed frame to a desirable height. The mattress frame supports a mattress. The bed frame, mattress frame and mattress make up a standard bed structure. However, the mattress frame typically cannot function without the cooperation of a bed frame. Structural support for the bed comes mainly from the bed frame underneath. In most applications, the mattress frame is made of a light, inexpensive wood such as pine. However, the rejection rate of the wood used to manufacture a typical mattress frame can be as high as 15% due to natural faults in the wood leading to large amounts of waste. The mattress frame is stapled together during manufacture and serves only as a support for the internal components of the bed frame, springs, padding covers and the like. The bed frame is typically made of angled steel and offers more than adequate support for any average bed loading.

The purpose of the mattress frame or box-spring is threefold; to raise the mattress' height, to absorb shock and reduce wear to the mattress, and to create a flat and firm structure to support the mattress.

U.S. Pat. No. 6,966,085 to Cretsinger, et al. discloses sleep system providing a bed including a frame with cross support members coupled with panel assemblies. The frame includes two rail members and two end rails connected by corner connectors. The corner connectors incorporate a tongue and groove assembly for connection. The Cretsinger device incorporates many intricate parts which complicate the manufacturing process and exhaust unnecessary amounts of material.

U.S. Pat. No. 5,561,876 to Petruzella discloses a mattress like structure of a rigid tubular plastic material such as polyvinyl chloride including a generally rectangular shaped rigid frame, a pair of opposed sides, a pair of opposed ends, frictionally engaged elbows which serve to connect the sides and ends to form the rectangular frame, and a flexible fabric tightly stretched over the frame to form a top and bottom surface wherein the frame is of a type that is easily assembled and disassembled into its component parts. The Petruzella device is not easily re-configurable and does not support a mattress as it is the mattress itself.

U.S. Pat. No. 5,469,589 to Steed, et al. discloses a bed foundation comprising a pair of parallel spaced side rails with ends connected by corner braces to the ends of parallel cross rails thereby defining a rectangular box frame wherein the side rails and cross rails may be constructed from a thermoplastic compound. The Steed device requires additional hardware for assembly.

U.S. Pat. No. 7,003,822 to Sheehy discloses a “knock-down” bed frame assembly formed from extruded plastic components including a frame having a pair of side rails, a pair of end rails, and connector brackets wherein the entire knock-down bed frame can be disassembled into individual components that can be contained within a conventional shipping container. The Sheehy device requires extra hardware for assembly and incorporates additional connecting pieces between the side rails.

U.S. Pat. No. 6,832,397 to Gaboury, et al. discloses a bed foundation made from blow molded plastic material, having interlocking joints between rails and between joists and rails. When assembled, it has a top panel which overhangs the side rails to permit an oversized mattress to be placed thereon. It may be assembled without the use of tools. When disassembled the components compactly ship within a container. The Gaboury bed foundation requires additional hardware for assembly of the connecting joints.

It is desirable to have a mattress support system that is lightweight, durable, flexible, configurable, is easily manufactured of common inexpensive materials, and minimizes total material used to avoid waste. It is also desirable to have a bed frame of sufficient strength to support normal loading without deformation. It is also desirable to eliminate the need for a bed frame by strengthening a mattress frame to support additional loading. The art is replete with mattress frames and bedding apparatus, but none include all the features and functionality disclosed herein.

SUMMARY OF INVENTION

An embodiment of the apparatus includes a pair of side rails connected to a pair of end rails via four end caps to form a lightweight, durable mattress frame in generally rectangular shape which minimizes the amount of material used and eliminates extra fastening hardware. The side rails and the end rails may vary in length depending on the particular use desired but each of the side rails and end rails has an identical cross-section shape made up of five sections surrounding a slot. The end caps are a generally quarter circle shape and each includes two tabs for insertion into the slots of the side rails and end rails. The side rails and end rails further include encapsulated steel ribs.

In an alternate embodiment, the side rails, end rails and end caps incorporate strengthening inserts to the frame. In another embodiment, feet are included to raise the mattress frame in order to eliminate the need for a bed frame.

In an alternate embodiment, slats are included for added strength and to support springs internal to the mattress frame. The slats can extend from side rail to side rail or from end rail to end rail. Depending on the amount of added strength required for a particular use, one or a plurality of slats can be added. Each slat has a generally U-shaped cross section and further includes encapsulated strengthening ribs.

Those skilled in the art will appreciate the above-mentioned features and advantages of the invention together with other important aspects thereof upon reading the detailed description that follows in conjunction with the drawings provided.

BRIEF DESCRIPTION OF THE DRAWINGS

In the detailed description of the preferred embodiments presented below, reference is made to the accompanying drawings.

FIG. 1 is an isometric view of a preferred embodiment where a mattress is in shadow.

FIG. 2 is partial isometric view from the bottom of a preferred embodiment of the mattress frame.

FIG. 3 is partial isometric view from the top of a preferred embodiment of the mattress frame.

FIG. 4 is a partial plan view of a preferred embodiment of a side rail.

FIG. 5 is a partial plan view of a preferred embodiment of an end rail.

FIG. 6 is an isometric view of a preferred embodiment of and end cap.

FIG. 7 is a partial exploded isometric view of a preferred embodiment of an end cap, a side rail, and an end rail.

FIG. 8A is a cross-section of a preferred embodiment of a side rail taken along line 7-7 of FIG. 3.

FIG. 8B is a side view of a preferred embodiment of a rib.

FIG. 9 is a partial plan view of a preferred embodiment of a slat.

FIG. 10 is a cross-section of a preferred embodiment of a slat taken along line 9-9 of FIG. 9.

FIG. 11 is an isometric view of a preferred embodiment including longitudinal and lateral slats.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

In the descriptions that follow, like parts are marked throughout the specification and drawings with the same numerals, respectively. The drawing figures are not necessarily drawn to scale and certain figures may be shown in exaggerated or generalized form in the interest of clarity and conciseness.

Referring to FIGS. 1-5, mattress frame 100 is comprised of a pair of side rails connected to a pair of end rails via end caps. In the preferred embodiment, the side rails and the end rails are made of an extruded polyvinyl chloride (PVC) plastic, but other lightweight, flexible plastics will suffice. In the preferred embodiment, the end caps are made of a fiber reinforced nylon consisting of at least 20% glass or Kevlar® fibers. Side rails 102 and 104 are generally longer in length than end rails 106 and 108 so when assembled as shown in FIGS. 1-3 form a generally rectangular shape and are comprised of the dimensions typical of bed frames and mattresses found in the industry. It is understood that different ratios than those depicted could be incorporated to construct bed sizes including but not limited to twin, double, queen, and king size. It is also possible that the side rails and the end rails are of the same length to create a generally square shaped frame. Side rails 102 and 104 have the same cross-section shape as end rails 106 and 108. FIG. 1 shows mattress frame 100 as would be incorporated within box springs 150 (shown in shadow) where box springs 150 would include springs and fabric cover as is common in the art. A set of four feet 195 is included to raise the mattress frame when in use.

End cap 120 connects side rail 102 to end rail 106. End cap 122 connects end rail 106 to side rail 104. End cap 124 connects side rail 104 to end rail 108 and end cap 126 connects end rail 108 to side rail 102 to form the four sided mattress frame 100.

Referring now to FIGS. 6 and 7, end cap 120, side rail 102, and end rail 106 is shown. It is understood by those skilled in the art that end caps 122, 124, and 126 are identical to end cap 120 and thus will not be described further. End cap 120 is comprised of a middle section 930 and two tabs 920 and 922. It is understood that each end cap is integrally formed. Middle section 930 is shaped in a quarter circle and includes outside curved edge 904, edge 909, inside curved edge 902, edge 906 and an approximately centrally positioned hole 197. The height of outside curved edge 904, edge 909, inside curved edge 902, and edge 906 is generally equal to the height of sections 404 and 408 of the side rails and end rails. Outside curved edge 904 is connected to a first end of edge 906 and a first end of edge 909. Inside curved edge 902 is connected to a second end of edge 906 and a second end of edge 909 and includes hole 197 located generally at the midpoint. Braces 907 and 908 extend radially from inside curved section 902 to outside curved section 904. Edges 906 and 909 extend past inside curved edge 902 to meet and form a generally right angle shown as corner 910. The height of corner 910 is generally equal to the height of slat support 406 and tab support 414 of the side rails and end rails. Extending generally perpendicularly from edge 906 is tab 920. Extending generally perpendicularly from edge 909 and generally perpendicular to tab 920 is tab 922. The tabs include braces 918 and 919. Both tabs 920 and 922 are shown having a generally L-shaped cross-section. It is understood that the cross-section of tabs 920 and 922 could be other shapes adapted to fit within the slots of the end rails and side rails.

Four feet 195 are provided, each of which incorporates a single threaded stanchion 196. Threaded stanchion 196 is adapted to engage threads inside hole 197. In an alternate embodiment, threaded stanchion 196 extends through hole 197 and is retained in place by a nut (not shown). The width of each foot 195 is sufficient so that it extends from edge 909 or the base of tab 922 to edge 906 or the base of tab 920, thereby supporting end cap 120.

Referring to FIG. 8A, cross-section 400 of side rail 104 is shown. The cross-sectional dimensions of side rails 102 and 104 and end rails 106 and 108 are identical. Cross-section 400 shows that the side rails and end rails are comprised of five sections configured to form an opening leading to a slot. Each side rail and end rail are integrally formed.

Section 404 extends generally perpendicularly from slat support 406. Section 402 extends generally perpendicularly from section 404 in a direction away from slat support 406 and is also generally parallel with slat support 406. Section 408 extends generally perpendicularly from section 402 in a direction towards slat support 406 and is generally parallel with section 404. Tab support 414 extends generally perpendicularly from section 408 in a direction towards slat support 406 and is parallel to section 402 and slat support 406. Between tab support 414 and slat support 406 is gap 410 which leads to slot 412. Slot 412 is surrounded by sections 404, 402, 408, tab support 414, and gap 410. Slot 412 is depicted as rectangular shaped but other polygonal shapes would suffice. It is understood that the shape of slot 412 paired with gap 410 should permit connection with tabs 920 and 922. Section 404 includes rib 422. Section 408 includes rib 420. Ribs 420 and 422 are galvanized steel bars running the full length of each side rail and end rail. In an alternate preferred embodiment, in order to reduce weight further, the ribs are not present. In other preferred embodiments, the ribs are constructed from a heavy gauge steel mesh, fiberglass, Kevlar® or aluminum.

Referring to FIG. 8B, the ribs of the preferred embodiment include knurled surfaces 700 on both sides to aid in bonding with the plastic encapsulation to achieve a unitary construction. The positions of the knurled surfaces are shown at each end of the rib. In other embodiments, additional knurled surfaces are included as other lengths along the rib. The ribs also include holes 702 to reduce weight and aid in bonding with the plastic encapsulation. In a preferred embodiment, the height “x” of ribs placed in longer side rails is increased compared to those of the end rails to offset greater bending loads. In another embodiment, the cross-section shape of the ribs is an “I”-beam in order to withstand additional weight.

In use, side rails 102 and 104 are connected to end rails 106 and 108 via end caps 120, 122, 124, and 126. At each corner of mattress frame 100, tabs 920 and 922 are inserted into slots 412 and gaps 410 as is shown in FIG. 7. The corners and ribs are held together with a tolerance press fit. There is no need for additional tools or connecting hardware to assemble mattress frame 100. Ribs 420 and 422 provide extra strength for the side rails and end rails. Mattress frame 100 is then attached to box springs 150 with staples or adhesive as is common in the art.

The preferred method of manufacture of the end rails and side rails includes extrusion through a co-extrusion die such as is known in the art. In the preferred embodiment, the steel insert is fed into the die. The PVC plastic is then extended through the co-extrusion die as the insert material is deployed from a roll. The steel insert is pre-heated through induction heating, or other methods known in the art, until the plastic adjacent the metal insert fuses around and into the metal insert. After cooling, the side rail or end rail may be considered integrally formed or “encapsulated.” Other methods of molding or encapsulation may be used with equal success.

Referring to FIGS. 1, 9 and 10, slat 900 is shown. Slat 900 is comprised of three sections forming a “U-shape.” Slat 900 is one continuous piece of material. Base section 906 is flanked by sections 902 and 904. Sections 902 and 904 are both generally perpendicular to base section 906 and are generally parallel to each other. Section 902 includes rib 922. Section 904 includes rib 920. Ribs 920 and 922 are galvanized steel bars running the full length of slat 900. Ribs 920 and 922 provide extra strength for the slats.

In an alternate preferred embodiment, a single or a plurality of slats can be incorporated in mattress frame 100 as shown in FIGS. 1 and 11. Slats can be positioned perpendicularly to the side rails and parallel to the end rails (lateral slats 940) or parallel to the side rails and perpendicular to the end rails (longitudinal slats 950). When in place, one end of slat 900 is adjacent to section 404 and rests on slat support 406 of a side rail or end rail while the opposite end of slat 900 is adjacent section 404 and rests on slat support 406 of an opposing side rail or end rail. The location of slats 900 relative to each other and relative to the end rails or side rails depends on the amount of support and flexibility desired. Where more support is required, additional slats can be added. For added support, slats 900 can be pinned to the side rails and end rails with rivets or similar attachment hardware as is common in the art. In an alternate embodiment, the slats are bonded to the end rails and side rails with a suitable adhesive or inductive welding.

When both longitudinal slats 950 and lateral slats 940 are incorporated in mattress frame 100, longitudinal slats 950 are placed adjacent section 404 and slat support 406 of opposing end rails as previously described with the U-shape facing downwards. Lateral slats 940 are then placed on top of and generally perpendicularly to longitudinal slat 950 and additionally rest on section 402 of the opposing side rails with the U-shape facing upwards. At the intersection of the slats, the slats can be pinned together with rivets or similar attachment hardware as is common in the art. Additionally, adhesive or inductive welding may also be used to attach the intersecting slats together.

It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims. 

1. A mattress frame comprising: a first non-metallic side rail connected to a first non-metallic end rail by a first end cap; the first non-metallic end rail connected to a second non-metallic side rail by a second end cap; the second non-metallic side rail connected to a second non-metallic end rail by a third end cap; the second non-metallic end rail connected to the first non-metallic side rail by a fourth end cap; the first non-metallic side rail, second non-metallic side rail, first non-metallic end rail and second non-metallic end rail each having a cross-section; wherein the cross section comprises: a first section, second section and third section integrally formed to define a rectangular channel; a tab support, attached to the first section, adjacent to and extending into the rectangular channel; and a slat support, attached to the third section and extending away from the rectangular channel.
 2. The mattress frame of claim 1 further comprises: a first metallic strengthening rib, encapsulated in the first section; and a second metallic strengthening rib, encapsulated in the third section.
 3. The mattress frame of claim 2 wherein the first metallic strengthening rib encapsulated in the first section of the first side rail and the second metallic strengthening rib encapsulated in the third section of the first side rail are of greater height than the first metallic strengthening rib encapsulated in the first section of the first end rail and the second metallic strengthening rib encapsulated in the third section of the first end rail.
 4. The mattress frame of claim 2 wherein the first metallic strengthening rib includes a knurled section encapsulated by the first section.
 5. The mattress frame of claim 2 wherein the first metallic strengthening rib includes a plurality of holes encapsulated by the first section.
 6. The mattress frame of claim 1 further comprising: a plurality of non-metallic slats, supported by the slat support of the first non-metallic side rail and the slat support of the second non-metallic side rail.
 7. The mattress frame of claim 6 where each of the plurality of non-metallic slats further comprises: a first vertical stanchion; a second vertical stanchion; a horizontal base section, connected to the first vertical stanchion and the second vertical stanchion; a third non-metallic strengthening rib encapsulated in the first vertical stanchion; and, a fourth non-metallic strengthening rib encapsulated in the second vertical stanchion.
 8. The mattress frame of claim 7 where: the third non-metallic strengthening rib includes a first knurled section and a first plurality of holes encapsulated in the first vertical stanchion; and the fourth non-metallic strengthening rib includes a second knurled section and a second plurality of holes encapsulated in the second vertical stanchion.
 9. The mattress frame of claim 1 where the first end cap further comprises: a non-metallic arcurate corner having an inside semi-cylindrical wall integrally and an outside semi-cylindrical wall; the inside semi-cylindrical wall and the outside semi-cylindrical wall connected by a first radial vertical wall and a second radial vertical wall; the first vertical wall and the second vertical wall forming a generally right angle; a first tab extending generally perpendicularly from the first vertical wall; a second tab extending generally perpendicularly from the second vertical wall; wherein the first tab removably engages the first non-metallic side rail; and the second tab removably engages the first non-metallic end rail.
 10. The mattress frame of claim 9 further comprising a foot, removably secured to the non-metallic arcurate corner.
 11. The mattress frame of claim 10 wherein the first tab further includes a first longitudinal strengthening channel and the second tab includes a second longitudinal strengthening channel.
 12. The mattress frame of claim 2 further comprising: a first plurality of non-metallic slats, extending from the slat support of the first non-metallic end rail to the slat support of the second non-metallic end rail; a second plurality of non-metallic slats, supported by the second section of the first non-metallic side rail and the second section of the second non-metallic side rail and adjacent to and intersecting generally perpendicularly with the first plurality of non-metallic slats; wherein the first plurality of non-metallic slats and the second plurality of non-metallic slats each comprise: a first vertical stanchion; a second vertical stanchion; a horizontal base section, connected to the first vertical stanchion and the second vertical stanchion; a third metallic strengthening rib encapsulated in the first vertical stanchion; and, a fourth metallic strengthening rib encapsulated in the second vertical stanchion.
 13. A mattress support comprising: a first non-metallic rail, having a first longitudinal slot, a first tab support adjacent the first longitudinal slot and a first slat support parallel to the first tab support; a second non-metallic rail, having a second longitudinal slot, a second tab support adjacent the second longitudinal slot and a second slat support parallel to the second tab support; a third non-metallic rail, having a third longitudinal slot, a third tab support adjacent the third longitudinal slot and a third slat support parallel to the third tab support; a fourth non-metallic rail, having a fourth longitudinal slot, a fourth tab support adjacent the fourth longitudinal slot and a fourth slat support parallel to the fourth tab support; a first corner piece, having a first tab perpendicularly opposed to a second tab; a second corner piece, having a third tab perpendicularly opposed to a fourth tab; a third corner piece, having a fifth tab perpendicularly opposed to a sixth tab; a fourth corner piece, having a seventh tab perpendicularly opposed to an eighth tab; the first tab contacting the first tab support and removably joining the first longitudinal slot; the second tab contacting the second tab support and removably joining the second longitudinal slot; the third tab contacting the second tab support and removably joining the second longitudinal slot; the fourth tab contacting the third tab support and removably joining the third longitudinal slot; the fifth tab contacting the third tab support and removably joining the third longitudinal slot; the sixth tab contacting the fourth tab support and removably joining the fourth longitudinal slot; the seventh tab contacting the fourth tab support and removably joining the fourth longitudinal slot; and the eighth tab contacting the first tab support and removably joining the first longitudinal slot.
 14. The mattress support of claim 13 wherein: the first non-metallic rail encapsulates a first pair of vertical strengthening ribs; the second non-metallic rail encapsulates a second pair of vertical strengthening ribs; the third non-metallic rail encapsulates a third pair of vertical strengthening ribs; and the fourth non-metallic rail encapsulates a fourth pair of vertical strengthening ribs.
 15. The mattress support of claim 14 wherein: the first pair of vertical strengthening ribs includes a first plurality of roughened surfaces and a first plurality of holes; the second pair of vertical strengthening ribs includes a second plurality of roughened surfaces and a second plurality of holes; the third pair of vertical strengthening ribs includes a third plurality of roughened surfaces and a third plurality of holes; and the fourth pair of vertical strengthening ribs includes a fourth plurality of roughened surfaces and a fourth plurality of holes.
 16. The mattress support of claim 14 wherein the: first pair of vertical strengthening ribs is formed of one of the group of steel, aluminum, fiberglass and Kevlar® fibers.
 17. The mattress support of claim 16 wherein: each slat of the plurality of non-metallic slats encapsulates a pair of vertical strengthening ribs.
 18. The mattress support of claim 17 wherein: each of the pair of vertical strengthening ribs includes a set of roughened areas and a set of holes.
 19. The mattress support of claim 18 further comprises: a first foot removably attached to the first corner piece adjacent the first tab and the second tab; a second foot removably attached to the second corner piece adjacent the third tab and the fourth tab; a third foot removably attached to the third corner piece adjacent the fifth tab and the sixth tab; and a fourth foot removably attached to the fourth corner piece adjacent the seventh tab and the eighth tab
 20. The mattress support of claim 14 further comprising: a first plurality of non-metallic slats, extending from the first slat support of the first non-metallic rail to the third slat support of the third non-metallic rail; a second plurality of non-metallic slats, supported by the second non-metallic rail and the fourth non-metallic rail and adjacent to and intersecting generally perpendicularly with the first plurality of non-metallic slats; wherein the first plurality of non-metallic slats and the second plurality of non-metallic slats each comprise: a first vertical stanchion; a second vertical stanchion; a horizontal base section, connected to the first vertical stanchion and the second vertical stanchion; a first metallic strengthening strip encapsulated in the first vertical stanchion; and, a second metallic strengthening strip encapsulated in the second vertical stanchion. 